Hacksaw-machine.



L. S. STAR'RETT.

HACKSAW MACHINE.

APPLICATION FILED FEB. 5. 1916.

Patented Nov. '6, 1917.

4 SHEETS-SHEET I.

[12 1/67? for Zoroyd. darrcit j Aiiarngg L. S. STARRETT.

HACKSAW MACHINE.

APPLICATION FLLED FEB. 5. 1916.

Patented Nov. 6, 1917.

4 SHEETSSHEET 2.

I 5; [22 vcnio'r liangy $630771??? L. S. STARRETT. HACK SAW MACHINE.

APPLICATION FILED FEB. 5. I916. I 1,245,815. Patented Nov. 6, 1917.

4 SHEETS-SHEET 3.

L. S. STARRETT.

HACKSAW MACHINE.

APPLICATION FILED FEB. 5. I916.

Patented Nov. 6, 1917,

4 SHEETS-SHEET 4.

LaRoYssTARRE T, 0F ATE-10L, messaonosm rs, essieivon Tomlin L. -.s. saaimrnir COMPANY, or ATHOL, IvrassAoHUs-Er'rs, A oonroim'rioivor (MASSACHUSETTS.

, HAoKsAW-Maenmn Y T 0 all whom it may concern: 7

Be it known that I, Leno r Summit, a citizen of the United States, residing at Athol, county of flllorcester, Commonwealth of Massachusetts, have invented certain new and useful Improvements ihfHacksaw-Machines, of which the followingis a specification. i

This invention relates to ,thecontrol or feed of hack saw machines'of the gravity type and particularly to such control ofthe machines shown and described (,but not claimed), and to the combination of the control with themachine. a

In such gravity fed sawing machines, there is a destructive tendency which seriously lessensthe otherwise great advantages of the gravity feed. v This tendency results in broken saw blades, mutilatedwork,and

damage to the machine'by shock, and even involves risk to the operator of the machine. It is the ob ect of my present invention to provide means for overcoming:this tendency-in saw machines in general an'dfi n' pa r ticular to embody the invention in a combinatlon with a machlne in which there is a peculiar need and in which it hasi a combined and modified effect.

The embed nentiof myinvention in practical form is shown in the accompanying drawings in combination with the machine (not claimed) with which it most effectively combines It ,should be ,understoo d'however, that while especially adapted for use in a machine of the typeshown, my invention may be used in any hack-saw'machine in which the frame is adapted to be l fted from they work. In brief, my invention con-- sists in floating a gravity fed saw frame which normally has no lifting eflect during its reciprocations on a. by-passedoil cylinder, .and in providing .a mechanical lift effective for a free upraising of the saw, though controlled inreverse direction by the check cylinder. *Heretofore, When placing new work in the machine, the saw frame has-usually been raised by hand. This is objectionable, both because of the extreme weight of the frame and its mechanism, and because it requiredthe use of the hands at the very time when needed for inserting and adjusting'the new work in the work clamp. By my-construc tion, the operator is relieved of this manual lift, and the saw frame is raised by the Specification of Letters Patent. m lica o tram ay 5, 19( 6- se iellie 45 Paatented N ovefi, '.o

weight of the operator exerted upon a treadle connected to the frame. This leaves the operators hands-free, as well as enabling the saw frame to be more easilyraised. The saw frame is supported in its position by the oil pistomthus allowing the operatorto give his full attention to the manipulation of the work. 1

Throughout specification and drawings, like reference numerals indicate corresponding part s,'and in the ,dravving, i

'F'gur'e 1, is an elevation of one side of a machine equipped'with my invention. 'Fig. "2, is an elevation of the machine from the opposite side, with-the saw raised. Fig.3, a detailofthe saw supporting construction was applied [to themachine shown. a

Fig; 4 is a further detail thereof, and Fig. i

nism, removed. Y a v "Inorder-to make clearlthe use and appli-- cation of my invention, "I will ole'scribe the general construction of the particular'mw chineto which my inventionhas been applied, and with which it effects a particular combination; Y

The machine is mounted on a suitable pedestal, -*1,-having a fiat top, 2, to which is bolted a bed-plate,-3. The clamp -for hold ing the work comprises pairof jaws, 4 and 5, the former being afixed aw, and-the latter a movable jaw,'guided in'"-ways 6, formed on the bediplatee, and usted 1011- gitudinally -there'of,' by" a --feed screw- 7, mountedin the bearing8,on the bed-13', and provided atfits outer end-with an operating crank 9. A vertically adjustable r eciprocating saw frame 11,- 'is'pjrovided at op positeends with bearings 11, in which are mounted stems 12- to which the saw blade 1-3'is detachably connected, being held at a 5 is a view'of'the release 'pin ofsaid mechaslight angle tothe frame back so that'it gain'sclearance on the non cuttingstroke.

and swings about-said shaft as a-pivot.

'llhehoriz ontally disposed pivot arm 25 c'arries thesaw fia1ne,;and;fhas downwardly extending forked end '26, which forms bear ings, through which a bushing 27, about the power shaft '28 is secured. The feeding pressure may be applied to the saw frame in any suitable manner, as by the weights shown in the drawings. The sawframe is reciprocated from the power shaft by suitable connections which convert the rotation of the power shaft to reciprocate the frame as shown. This connection consists of a vertical rocker arm 5L9, pivoted at to the bed plate 3 and connected by a pitman 5a to the saw frame 11. The rotation of the power shaft 28 through the crank 15, swings the lever 19 to reciprocate the saw frame 11 through the pitman connection.

In this type of machine, means are provided for relieving the saw frame of the feed pressure on the return or non-cutting stroke of the saw, without lifting the saw frame so as not to subject the teeth of the saw blade to strain and wear of contact while being withdrawn. This pressure re 1 lieving means, consists of a curved link 58,

pivoted to the saw guide 21. This curved link or segment works between a spring tension plunger 60, havinga cylindrical head 61, and the bearing of an oppositely disposed release pin 72. The .end of the plunger is exposed to the link 58, and is formed as a bearing face rounded circumferentially to conform to the link 58, but

flat in the direction of its width so as to provide the same bearing to the link at all points across the exposed face. The spring permits an automatic take-up of any Wear in the segmental link or in the face of the plunger. The plunger 60 is mounted for reciprocation in the chamber end 6:2 of a cam actuated lever 63, pivoted at one end at 6st to a casting 164: rising from the bed 3, and having a roll at its other end, disposed for alternate engagement and release by a cam 66, fast. on the shaft 28. Within the chamber 62, and between the rearwall thereof, and the head 61 of the plunger, is a coiled spring 67 the normal tendency of which is to maintain the head 61 in gripping contact with the link 58. Beyond the rear wall the plunger stem is threaded as indicated at 68, to receive one or more check nuts 69 to hold the adjustment of the plunger. The plunger is held against rotation by a set screw 71, bearing in a channel 7 O.

The plunger head is normally engaged with the curved link 58 by the action of the spring 67. When the machine is started it is necessary to release this engagement in order to permit the saw to descend on the 3 work. This release is effected manually through the pin 72, rotatably mounted in a. bearing 73 and having a flattened portion 74, against which a release stud 75 bears. An operating handle 77 is provided to rotate the pin 7 :2, thereby causing the flattened portion 74 to move the stud 75 against the head of the plunger 60, overcoming the spring 67 and causing the head to release the member 58. As soon as the stud 75 is released at the beginning of the cutting stroke, the pressure of the spring 67 is released, and the plunger is returned to position to again grip the link 58. This gripping however, does not become effective until the cam 66 has made a half revolution, thus bringing its dwell against the cam roll of the lever 63. This moves the lever toward the link to positively grip it on the return stroke of the saw.

It will therefore be seen that the link 58 is alternately released and gripped on each cutting and non-cutting stroke respectively. This alternately subjects and relieves the saw to the feeding pressure of the weights 35.

In order to prevent shock on the teeth when. the saw is released at the end of each return stroke, and in order to permit the saw to settle into the cut gently and without shock so that it will be floated as it were,

during its cutting action, I interpose between the pivoted arm 25 carrying the saw frame and the bed plate 3, a suitable motion checking device which in the embodiment shown, 18 in the form of an oil piston. As shown in Fig. 3 most clearly, I provide a cylinder 108 formed at its lower end to receive a fastening 107 which connects this end of the cylinder to bed 3 of the machine. This cylinder is adapted to be filled with any proper fluid such as a heavy oil, and'is provided with a suitable closure at its upper end. The piston stem 110 is pivoted at its upper end at 106 to the saw frame arm 25 and passes through a cap 109 inclosing a stuffing box 111 in which a packing is compressed by a cap 112 screwed on to the reduced projected end of the closure cap 109. The lower end of the stem is reduced: as indicated at 113, and carriesa disk .11 1 adapted to seal a plurality of openings 115 in a piston 116, slidably fitting within the casing 108, and having an extended hub 117, sleeved about the reduced end of the stem, whereby to move with said stem. Bearing against the lower edge of the hub 117, and confined between it and the-head of a screw 118, set in the lower end of the stem 110, is a coil spring 119, the normal tendency of which is to maintain the members 114 and 116 in sealing relation.

In my construction, the operator is re lieved of the necessity of manually raising the saw frame and of holding it in a raised position while inserting new work into the work clamp, thus leaving his hands free to properly adjust the work. The saw frame is raised by the weight of the operator ap;

:neasgsis I s plied to atreadle T pivoted near the .base

' of the machine-frame and ,operatively connected to the saw frame supportingarm 26 the raising of thearm 26 lifts the-stem llO' from the position :shoWn in Fig.3, to the position shownin Fig. 2, against the pressure-of thefluid as it passes through the opening "115.- This pressure is sufficiently great to counteract the tendency of the spring 11-9-,-*to' maintain the members 114 and 116 in s'ealed relation, andtherefore'permits the separation of said members and a consequent passage of the fluid through the openings 115 from above the piston to theside' below. I

- This action is entirely automatic and the dash pot'there'forefnot only permits the saw 'release' of the saw the gripping device,

but also assists to che'ck vibration, and tends to keep the saw blade steady-inthe 'kerf'during the cutting action. operation therefore, the saw "frame is raised 'by the foot trcadle T, leaving the hands of the" operator free to make adjustments} of tlie machineor the WOIkL This-"raising movement is resisted slightly through the oil; cylinder so that the saw 'r;1ses"\vith-a' smooth and steady motion,

leasing on each reciprocationfit finally comes in contact with the-Workgently and steadily and Without shock or jar; and Without danger of breaking the teeth or of losing its alinement I the cutting operation, and. at each release of the gripping mechanism, the oil plston floats the saW so that the resultant feed is no longer a series of sudden checksand releases, but is a merglng movement in whlch the action is a buoyant relief sustained during each return stroke by the gripping action of the machine.

My invention may obviously be applied to various modifications of the machine shown, and may be embodied in mechanism of different sorts Without departure from the spirit of my invention, if Within the limits of the appended claims.

- What I therefore claim and desire to secure by Letters Patent is:

1. In a cutting machine, a means for imparting a cutting to, gravity means for exerting on said cutting element, and means for 1nterrupting the feed tendency of said pressure means during the non-cuttlng stroke of the cutting element to permit said element to be returned to position to begin a cutting element,

stroke there- As thes'avv'is" released to 7 make its initial"contact'with'th'e- Work,'-its descent is c'ontrolledsojthat as it moves to the Work during the rapid gripping and re- V and "Without shock-under the teed tendency with the out) Throughout feed pressure new cutting strokefivvithout Iiftingsaid-gelement from :thecut previously made "and; in

substantially the "line traversed bylsa id element on thecutting stroke,said m'eanszautomatically I releasing said 2 feed "pressure means when said cutting element is :in iposition tobegm a newcutting stroke; 'EHCLIDQELIIS effective upon suclrrelease to prevent abrupt dropof' said cutting element.

2; In a cutting machine, a powera sha=ft,- a 1 cutting element reciprocated iatheretrom, gravlty means for exerting feed! pressure. 'on

a said element during the cuttingistroke thereof, means actuated from: said power shaft fective' I upon a such release and: permitting and adapted to 1ntertnittentlygrip: rand s-re-jv,

said, element "to settle into the "cut'gently and Without slioc'k -under the feed tendency of the now released a pressure means." I

' "3.111 a cutting machine;a z-power shatt; a cutting element -r'eciprocatedciik'therefrom, gravity means for T exerting: feedjpressureron said element duri ng the cutti ng -stroke thereof, and means I actuated from said; power shaft and adapted to intermittentlygrip and release said elei'nent, thereby to alternatel-y interrupt and release" the; gravity; tendency of sald' feed pressure nreans, and.

a" dash pot*interposed between isaidv ele'mont effective upon P such release" to 'permit (said element to settle doWn i into. the 1 e'ut'r: gently Q of the now releasedpr'essure-Jmeans.

"1' 4. 111 a sawing mac1'1'ine,:raframe, av saw frame pivoted thereon, gravity means for leasing the gravity'tendency of said feed pressure means, and a dash pot interposed between the pivotal connection for the saW frame and the frame of the machine and operated by 'the'movement of said saw frame for automatically checking the feed tendency of the pressure means after release thereof to permit the saw to settle gently to the vWork. c

5. In a cutting machine, ,a cutting element, means'for exerting feed pressure thereon, a member to be gripped associated With said element, a gripping mechanism for alternately gripping and releasingsaid,

member according to the position of said cutting element to alternately interrupt and release the normal feed tendency of the feed pressure means, and a device operated by the position of said cutting element for subsidingly sustaining said element When said feed pressure is released.

6. In a cutting machine, a cutting element, gravity means for exerting feedv presciated with said element, a gripping mechv sidingly sustaining said element when said anismfor alternately gripping and releasing said member accordlng to the position for said cutting element to alternately interrupt and release the normal gravity tendency of the feed pressure means, and a device interposed between said element and a fixed part of the machine and operated by the position of said cutting element for subfeed pressure is released.

7. In a sawing machine, a saw, a driving mechanism therefor, means for exerting feed pressure thereon, armember to be gripped, associated with said saw, a gripping device to alternately grip and release said member to interrupt and release the normal tendency of the feed pressure means according to the position of the saw, a release for said member to be gripped, designed to be manually operated to initially relieve said member of the grip of said vdevice, and means effective upon release of the feed pressure means to subsidingly sustain said saw. a r

8. In a cutting machine, a cutting element, means for normally exerting feed pressure thereon, means for locking said cutting element to relieve it of the feed pressure, means whereby said locking means is released to permit the feed, andrmeans for subsidingly sustaining the cutting element when the feed pressure is removed from said element.

9, In a cutting machine, a cutting element,

means for normally exerting feed. pressure thereon, means for automatically removing said feed pressure from the cuttlng element upon the non-cutting stroke, and for returnand means for subsidingly sustaining said element when relieved of the feed pressure.

10. In a machine saw, a reciprocable saw, means for normally exerting feed pressure thereon, means for automatically removing the feed pressure from the saw upon the non-cutting stroke and operating to allow the saw to be returned to position to begin a new cutting stroke without lifting from the saw cut and in substantially the line traversed on the cutting stroke, means for I raising the saw frame to permit the work to be changed, and means for subsidingly sustaining the saw in raised position.

11. In a machine saw, a reciprocablesaw,

means for normally exerting vfeed pressure I thereon, saw-looking means for automatically removing the feed pressure from the saw upon the non-cutting stroke and operating to allow the saw to be returned to position to begin a new cutting stroke without lifting from the saw cutand in substan tially the line traversed on the cutting stroke, means for raising the saw frame to permit the work to be changed, and a fluidoperated device for subsidingly sustaining H the saw in raised position.

In testimony whereof I affix my signature in presence of two witnesses.

LAROY S. STARRETT.

Witnesses: I

FRANK E. WING, FLORENCE E. Boron.

copies elf-this patent may be obtained for five cents each, by addressing the Commissioner of. Patents.

7 Washington, D. (6.1 

